The present invention generally relates to the field of loading docks, and more specifically to loading dock shelters that are positioned around a loading dock opening to provide a shelter between the loading dock and the open end of a vehicle (e.g., a truck or trailer).
Most warehouses, manufacturing facilities and large retail stores include loading docks that provide a location for loading and unloading vehicles. Loading docks typically include a raised platform and a dock opening positioned above the raised platform. The dock opening is formed by a dock wall having two vertical side portions extending upwardly from the platform, and a horizontal upper portion connecting the top of the side portions. A vehicle can back toward the dock opening until the back of the vehicle is abutting the platform. The platform sometimes includes a dockleveler that provides a ramp between the platform and the bed of the vehicle to facilitate loading and unloading of the vehicle (e.g., by a forklift).
Many loading docks include dock seals and shelters that provide a barrier between the dock wall and the back of the vehicle. For example, dock shelters can include rigid frame shelters that are made from wood or steel tubing. The rigid frame typically includes a head frame positioned above the dock opening and side frames positioned on opposing sides of the dock opening. Fiberglass panels or flexible fabric covers the frames. In addition, a head curtain and side curtains with flexible stays are positioned in front of the frames and are designed to contact the vehicle to provide a barrier between the inside of the loading dock and the exterior environment.
The above-described dock shelters provide good protection against the elements. However, as with most loading dock equipment, it must withstand repeated uses under a variety of weather and loading conditions. Any increase in longevity of the dock shelters would therefore be an improvement. In addition, simplified construction techniques and improved structural stability are desirable design goals.
A typical dock shelter 10 is illustrated in FIG. 1. The dock shelter 10 includes a frame 20 that is adapted to be mounted to a loading dock 12. The dock shelter 10 further includes a head curtain 26 that hangs from a top portion of the frame 20, and side curtains 28 that extend inwardly from respective side portions of the frame 20. The head curtain 26 and the side curtains 28 typically include flexible stays (not visible in FIG. 1) which add resiliency to the curtains to maintain a biased contact with different sized vehicles when the vehicles are positioned at the loading dock.
Referring now particularly to FIGS. 2 and 3, the curtains 28 are typically pre-assembled before they are shipped to the site of loading dock. A typical curtain 28 includes a weather-proof sheet 22 that has several pockets 24 mounted in uniform spaced parallel relation along the length of the sheet 22 (spacing is shown most clearly in FIGS. 1 and 4). The pockets 24 are adapted to receive flexible stays 27. One end of each stay 27 is typically inserted into a protective sleeve 23 before the stay 27 is inserted into the pocket 24. The sleeve 23 prevents the edges of the stay 27 from puncturing or prematurely wearing the sheet 22. The sleeve 23 is typically much smaller than the pocket 24.
A typical curtain 28 is assembled by punching or drilling a hole 25 in one end of the stay 27 prior to inserting the stay 27 into the pocket 24. Corresponding holes 26 are also punctured through the pocket 24 and the sheet 22. The stay 27, with the sleeve 23 mounted thereon, is inserted into the pocket 24 and then manually manipulated until the hole 25 in the stay 27 and the holes 26 in the sheet 22 and pocket 24 are aligned. The stay 27 is secured to the sheet 22 and the pocket 24 by inserting a grommet 30 into the aligned holes 25, 26 and then crimping the pocket 24, stay 27 and sheet 22 together using the grommet 30.
As shown most clearly in FIG. 4, the curtain 28 is assembled to the frame 20 of the dock shelter 10 by positioning the curtain 28 between an angled section 40 and the frame 20 and then securing the angled section 40 and the curtain 28 to the frame 20 using a wood screw 41. The angled section 40 typically includes pre-punched holes 42 such that each wood screw 41 is inserted through one of the pre-punched holes 42 in the angled section 40 and then through the grommet 30 before being threaded into the frame 20.
One of the drawbacks associated with using a grommet to secure the stay to the curtain is that the spacing between the pockets on the curtain often varies due to manufacturing tolerances. Therefore, the spacing between grommets often varies slightly. The varying distances between the grommets will result in one of two scenarios.
The first scenario has adjacent grommets farther from one another than the distance between the pre-punched holes in the angled section. In this first scenario, the grommets must be manually moved closer together as the curtain and angled section are assembled to the frame. The adjacent grommets are moved closer together until two of the adjacent pre-punched holes that are in the angled section are aligned with two adjacent grommets. Once the pre-punched holes and the grommets are aligned, wood screws can be inserted through the adjacent holes in the angled section and the corresponding grommets in the curtain. Moving adjacent grommets closer together before assembling the curtain and angled section to the frame causes the curtain to bunch under the angled section as the angled section and curtain are assembled to the frame.
The second scenario has adjacent grommets closer to one another than the distance between the pre-punched holes in the angled section. In this second scenario, only one of the adjacent grommets is able to receive a wood screw because the sheet in the curtain can only be stretched so far. As a result, the angled section and curtain must either be assembled to the frame using less than an appropriate number of fasteners, or an extra hole must be drilled through the angled section at a precise location which is aligned with the grommets. An alternative but more costly solution is to acquire a replacement curtain. However, the replacement curtain may also have the same problems.
These conventional curtains are also relatively expensive and difficult to assemble. As stated previously, the stay in a conventional curtain must typically have a hole pre-punched into the end of the stay that is positioned under the angled section. In addition, the pocket and sheet must have a hole pre-punctured hole in order to be able to receive a grommet. Finally, the stay must be manually manipulated until the hole in the stay is aligned with the pre-punctured holes in the pocket and sheet so that they may be crimped together by the grommet.
The present invention alleviates one or more of the above-noted problems by providing a curtain for a dock shelter that is easily assembled and is easily assembled in combination with other components as part of a dock shelter. The curtain of the present invention is designed to ensure that each of the stays in the curtain are easily and reliably inserted into the pockets on the curtain with the stays appropriately positioned in spaced, parallel relation on the curtain.
The curtain includes a sheet, preferably a weather resistant sheet, that has a pocket mounted thereon. The pocket is adapted to receive a flexible stay and includes slits. The slits in the pocket align and maintain the stay in the appropriate position within the pocket by inhibiting movement of the stay. For example, the pocket can include two slits, and the stay can be positioned between the two slits.
In one embodiment, the pocket of the curtain is folded under itself at one end before the pocket is secured to the sheet of the curtain. In this embodiment, the pocket can include a slit that is positioned substantially near, and parallel to, the folded end of the pocket. The resiliency of the pocket material near the folded end biases the slit outward away from the sheet such that the slit serves to prevent the stay from moving past the folded end of the pocket.
In another aspect, the invention relates to a method of making a curtain. The method includes the steps of securing a pocket to a sheet, forming a slit in the pocket (e.g., by cutting the pocket), inserting a flexible stay into the pocket, and positioning the stay adjacent the slit such that the slit inhibits movement of the stay.
In yet another aspect, the invention relates to a method of making a vehicle shelter and mounting the shelter to a loading dock. The method includes the steps of mounting a frame to the loading dock, securing a pocket to a curtain, forming a slit in the pocket, inserting a stay in the pocket adjacent the slit such that the slit inhibits movement of the stay, and placing the curtain against the frame.
It should be understood that the principles of the invention outlined herein could be used for both head and side curtains, which are typically part of a dock shelter, without departing from the scope of the present invention. Other principal advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description and the attached claims.